Why TI-83 wont turn on

If the above doesn't work, then you need to look at the contact springs from the batteries to the main board. The board flexes slightly when buttons are pushed and this causes there to be wear between the spring and board contact pad. In my calculator, the spring wore thru the contact pad. To reach the contact pads, you simply remove the 6 screws along the outer part of the cover. Then remove the screw covering the flat backup battery - just above the batteries. Get a small flat blade screwdriver and pry along the edge of the upper and lower covers (not the loose cover). Work along the edge and unsnap the 3 snap joints. There is one at the top center and one on each size approximately centered along the length of the battery. When you get the cover removed, look at the pads. You will probably see a black dot but if you look under a magnifying glass, you will see the bare circuit board. At this point, look at the pads to be sure there is no corrosion on them. It will look like a white or green powder. Remove with alcohol and Q-tip.

I tried the other solutions minus disassembly, but I flexed the body of my calculator by grabbing both sides and pushing the back with my thumbs. After that it displayed random numbers and letters, and then ram cleared and it turned on!

Did all and none worked, replaced my 4 triple A batteries hit the 2nd key and up arrow repeatedly and it came on saying Ram cleared, the I fixed contrast appropriately.

One more . . . Stretch the springs just a bit that contact the knob end of the battery... mine were pushed in and couldn't reach battery. Carefully!!!!!!!!!!!